PureYAML/CHANGELOG.md

Changelog

All notable changes to PureYAML are documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

Added

• Add PureYAML.parseStream(_:) for multi-document YAML streams, including explicit empty documents, document-end markers, and trailing comments before a following document start.
• Add PureYAML.Stream.Document, document-indexed stream validation issues, and stream validation APIs that preserve document indexes without changing document-local validation paths.
• Add stream dumping for [PureYAML.Stream.Document] with deterministic explicit document starts and existing emitter option support.
• Add merge-key expansion for plain << and explicit !!merge keys, including scalar merge mappings, sequence-of-mapping merge values, local override behavior, and exact errors for invalid merge values.
• Add PureYAML.parseTagged(_:) and PureYAML.parseTaggedStream(_:) for tag-preserving node trees, plus tagged validation rules for unsupported built-in tags and tags applied to the wrong node kind.
• Add PureYAML.Tagged.Constructor for caller-owned tagged construction with exact missing-handler and kind-mismatch errors, recursive path context, and an explicit model-value fallback that preserves mapping order and duplicates while erasing tags.
• Add first-class complex mapping keys through Model.Pair.keyNode, including parsing, deterministic validation paths, duplicate-key checks, and block/flow dumping for sequence and mapping keys.
• Add a real-world YAML fixture corpus with representative assertions for short, medium, and very large documents, including OpenAPI and Kubernetes examples.
• Add deliberately failing YAML fixtures that demonstrate exact validation diagnostics, strict failures, and non-strict warning returns.

Changed

• Tokenize YAML document start and end markers so scanner, event-parser, and stream tests can pin exact document-boundary behavior.
• Harden block mapping and multiline plain-scalar parsing around nested sequences, compact mapping entries, explicit complex keys, tagged keys, and lower-column mapping siblings.
• Keep quoted "<<": and explicitly string-tagged !!str << keys as ordinary string keys while merge syntax is expanded during parsing.
• Keep Foundation-backed tags such as !!timestamp and !!binary as ordinary model values in parse(_:); callers that need tag diagnostics can use the tagged parser and validator explicitly.
• Preserve anchors and tags on mapping values and sequence items whose actual node starts on the following indented line.

[0.1.0] - 2026-06-05

Added

• Bootstrap PureYAML as a root Swift package with no external dependencies.
• Add the first pure-Swift YAML model, parser, and dumper milestone.
• Add tests for block mappings, block sequences, common scalars, comments, and dump/parse round trips.
• Add path-aware YAML validation with duplicate-key checks, custom rules, and warning collection.
• Add the internal parse event model with marks, scalar styles, collection styles, alias events, anchor/tag metadata, and golden event tests for current parser behavior.
• Add the internal UTF-8 reader and scanner token layer with tests for comments, indentation, block entries, mapping indicators, flow delimiters, quoted scalars, block scalar headers, anchors, aliases, tags, and source marks.
• Add the internal scanner-token event parser for block collections, flow collections, aliases, anchors, tags, and line/column parser failures.
• Add the internal event composer and wire public parsing through scanner-token events into PureYAML.Model.Value, including flow collections, block scalars, anchors, aliases, and duplicate-key validation coverage.
• Add YAML directive and document-marker scanning, tag-handle expansion, and explicit built-in scalar tag composition for strings, integers, floats, booleans, and nulls.
• Expand tests into focused parsing, dumping, model, validation, and parse-error suites.
• Add macOS, Linux, and WASM verification gates and CI jobs, plus a local Linux check that can run through Claw Mini's Lima VM.
• Add a single full local verification script and wire pre-push through the macOS, Claw Mini Linux, and WASM gate sequence.
• Harden the changelog gate so local verification also sees unstaged source edits, not only committed or staged changes.
• Add emitter options with a selectable scalar policy for quoted strings or conservative plain-string output.
• Add opt-in literal block scalar emission for safe multiline strings, including |- parsing support for stripped final newlines.
• Add opt-in flow collection emission for compact mapping and sequence output.
• Add emitter corpus tests and document the current emitter policy.
• Add Yams and CYaml attribution without copying their implementation into Sources/.
• Add validation-rule predicates, a boolean validation-rule initializer, and validator authoring rules.
• Add scalar typed Decodable and Encodable conversion APIs with exact path-aware errors.
• Add unambiguous bracket-quoted validation paths for punctuation-heavy keys.
• Add keyed typed Decodable and Encodable conversion for mapping-backed structs.
• Validate YAML values before typed decoding so duplicate keys are rejected deterministically.
• Add unkeyed typed Decodable and Encodable conversion for sequences, including nested sequences and sequence properties on keyed structs.
• Add a fixture-backed sequence typed-conversion test corpus and a forbidden-pattern verification gate for package, source, and test contracts.
• Add broader Codable compatibility coverage for dynamic mapping keys, nested container round trips, keyed super coders, default super coders, and deterministic unsupported-shape errors.
• Add an explicit research-compatibility rule requiring parser, emitter, validation, and typed conversion work to start from PureYAMLResearch behavior without copying implementation code.
• Add a fixture-backed scalar and explicit-tag compatibility corpus with exact success, string-preservation, unsupported-spelling, and invalid-tag errors.
• Add a fixture-backed collection and anchor compatibility corpus with exact parsed values, parse errors, duplicate-key validation diagnostics, and pinned unsupported merge-key behavior.
• Add executable unsupported-gap fixtures for multi-document streams, complex mapping keys, unsupported directives, unsupported built-in tags, merge-key fallback behavior, and direct value-tree validation.
• Add fixture-backed literal block emission coverage for newly supported multiline content and exact quoted fallbacks.
• Add downstream-shaped document fixtures for API-style documents, service configuration decoding, and unsupported merge-key fallback behavior.
• Add usage and migration documentation that states tested APIs, support boundaries, unsupported YAML behavior, and cross-platform verification gates.

Changed

• Lower the package tools version to Swift 6.1 for hosted macOS CI compatibility and install Linux Swift toolchain prerequisites for the WASM CI job.
• Harden duplicate-key validation to use set membership while preserving exact diagnostics.
• Make validation rules immutable after construction.
• Preserve keyed super-encoder field order even when delayed child encoders are written in a different order than they were requested.
• Make keyed default superEncoder() and superDecoder() use the standard super mapping key instead of the current mapping.
• Resolve Yams-compatible plain scalar spellings for yes/no booleans, radix-prefixed integers, numeric separators, and .inf/.nan floats.
• Broaden opt-in literal block emission while preserving exact parser round-trips for every emitted block scalar.